This application claims the priority of 199 49 728.1, filed in Germany, Oct. 15, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a car seat, especially a motor vehicle rear bench seat with a seat back structure acting as a reclining back, and at least one cam plate to guide the back structure relative to a part affixed to the vehicle structure.
In known car seats of this kind, the seat-back structure is linked to top runners which are guided in rails affixed to the car""s structure. The user can adjust the inclination of the seat back by shifting the top runner so as to obtain different seat positions and seat back positions. The seat back structure is guided, for example, by cross bolts or cross rods in cam plates affixed to the car""s structure. In case of a frontal collision the danger exists that the seat back structure may be accelerated against the user, causing injury. Also there is the danger of xe2x80x9csubmarining,xe2x80x9d i.e., the user can slip under the lap belt.
The invention is addressed to the problem of improving a car seat of the kind described above. This problem is solved according to the invention by a car seat of the above noted type wherein between the cam plate and the part affixed to the vehicle structure, an element acting in case of a collision, is provided for the absorption of energy.
Inasmuch as an element is provided for energy absorption which acts between the slide and the part affixed to the vehicle, it is precisely at this point that a definite absorption and dissipation of the kinetic energy of the seat back structure is possible, which will protect the user against injury from the seat back structure and avoid the danger of submarining. Preferably, the element acting in a collision will be subject to a torsion. Thus the element will be able to absorb great forces without the need to be of especially stable construction.
In a preferred embodiment the cam plate runs forward, for example around a transverse tube. It then frees a path for a movement of the seat back structure, so that only the element acting in a collision will absorb the stresses. If the transverse tube is journaled in a bearing bracket affixed to the car""s structure and is permanently affixed to the slide, a unit is available which turns as a whole. The element acting in a collision is preferably disposed non-rotatably inside of the transverse tube so as to absorb the torque at one end. If the element is brought out of the transverse tube and inserted into the bearing bracket, the element is non-rotatably affixed at the other end to the car""s structure. The absorbed torque can then produce the torsion. To keep the element better in the bearing bracket when the stress is acting on it, so is will not be forced out of it, the element can be inserted through two lateral flanges of the bearing bracket. If the element is bent around the cam plate between the transverse tube and the bearing bracket, on the one hand the cam plate can turn freely, and on the other hand the element occupies little space. It is advantageous if the element is inserted into a disk which is fixedly mounted in the center of the transverse tube. Then the element can well absorb the torque, and on the other hand can be easily installed or replaced.
It is advantageous if in addition a catching belt acting in a collision is provided between the seat back structure, preferably its upper margin, and the car""s structure. The leverage of the forward driven seat back structure is then not so great.